Nanoprobes, Inc. has devised metal-enhanced radiation therapy [MERT], a method for cancer therapy that combines targeted delivery of heavy metal (such as gold) with tumor-focused gamma or x-ray irradiation. We now propose to study the application of MERT to solid tumors and to elucidate its mechanisms and limitations. Firstly, additional calculations and modeling will further our theoretical understanding. Secondly, the delivery of gold to human tumors in vitro and in nude mice will be optimized by examining four types of gold particles and three types of targeting molecules. Thirdly, the targeted gold will be irradiated to determine the efficacy. PROPOSED COMMERCIAL APPLICATION: If successful, Nanoprobes, Inc. will have developed useful targeted gold reagents useful for ancillary cancer therapy and management. These reagents would then have commercial importance.